1. Field of the Invention
The present invention relates to a non-contact rotational angle detecting sensor using a magnetically responsive element.
2. Description of Related Art
There is provided a non-contact rotational angle detecting sensor using a magnetically responsive element which can be structured to be downsized and has no possibility of a contact failure caused by foreign matters. For example, such a detecting sensor is a rotational angle detecting sensor of a non-contact type suitable for detecting a depressing angle of an accelerator pedal in a vehicle or detecting a rotational angle of a shaft rotating in response to an operation of a shift lever thereof.
For example, Japanese Patent Laid-Open Publication No. 5-505883 discloses the conventional art of such a non-contact rotational angle detecting sensor.
The conventional non-contact rotational angle detecting sensor 100 as shown in Japanese Patent Laid-Open Publication No. 5-505883 is constructed so that, as shown in FIG. 12, a ring-shaped permanent magnet 103 is attached through a back yoke 102 to a shaft (rotating element) 101 which is a detection object of a rotational angle, and a magnetic flux collecting yoke 104 is provided so as to surround an outer peripheral surface of the ring-shaped permanent magnet 103 at a constant gap.
The conventional non-contact rotational angle detecting sensor 100 detects a change of the magnetic field due to the ring-shaped permanent magnet 103 when the rotational element 101 rotates, by a hole IC 106 and detects a rotational angle of the rotational element 101 based upon the change of the detected magnetic field.